round - round floating point value
double round (x)
Round returns the integer closest to x in value. If the the fractional part of the operand is .5 or larger, it is rounded to the next larger integer value; otherwise, the operand is truncated to the next lower integer value.
With a MONEY value, round will round the MONEY value to the nearest basic currency unit (i.e., nearest penny for U.S.A. MONEY values).
C/Base Reference Manual Chapter 13, "Formatting Data Values"